Field
The present invention relates to improved hockey pucks used on non-ice surfaces. In particular, the invention relates to improved street hockey pucks which are generally designed for use on flat semi-smooth to rough surfaces with an increased rigidity.
Background
The most readily available non-ice surfaces for playing hockey are asphalt and concrete. They are the streets, parking lots and outdoor play areas at schools and parks. Because of the traffic and weathering, these surfaces are generally semi-smooth to rough. Hockey pucks designed for play on smooth surfaces perform very erratically on these surfaces. There have been many relatively recent attempts to design a puck that would work on these surfaces. Many of these recently patented pucks have not yet become commercially available. Several may prove to be too costly to manufacture and sell.
An example of such a puck is described in U.S. Pat. No. 5,568,923 Kanh et al. (1996). The preferred embodiment of this invention consists of 89 individual parts including 30 rollers. Obviously many of these parts would be designed out when it is manufactured. But, the basic design of the puck requires the use of many rollers, and making and assembling them will be costly. Such a design is too costly to be able to sell to the price sensitive market of school aged children.
Like Kanh et al., many pucks have used wheels or spheres to improve puck performance on rough surfaces. An example of another patented puck which utilizes many wheels is U.S. Pat. No. 5,518,238 Hu et al. (1996). The various embodiments disclosed in this patent utilize from eight to thirty wheels or from five to eighteen spherical rollers. The probable cost of manufacturing some of these embodiments may equal the cost of manufacturing the Kanh et al. puck. Not every patented puck, that utilizes rolling members, include as many as do these two. Several use just three spheres. Three such pucks are U.S. Pat. No. 4,793,769 Dolan (1988), U.S. Pat. No. 4,801,144 De Masi, Jr. et al. (1989), and U.S. Pat. No. 5,531,442 Gill (1996). While clearly these three would not be as expensive to manufacture, they do share a problem common to all pucks with revolving parts. The problem is the bearing surfaces are vulnerable to dirt and grit.
The asphalt and concrete surfaces have dirt, dust, sand and sometimes water on them. These things will get into the bearings or bearing surfaces of these types of pucks. The wheels and spheres will soon stop rolling and will not provide the function that they were designed to do. Spheres are particularly prone to failure. First there is no mechanical advantage to the sphere bearing. It is dependent on there being less friction between the sphere and its adjacent cavity, than between the sphere and the playing surface. As it is being used, dirt and grit will get between the sphere and the cavity. The sphere will also become scratched and gouged by stones embedded in the playing surface. The spheres will stop turning freely and will not help the puck travel smoothly over the playing surface. The dirt and dust will generally soon render pucks with revolving parts no better than pucks that were solid to begin with.
Solid pucks are not costly to manufacture, and that may explain why they seem to be the most commonly sold. Solid pucks also perform very badly on semi-smooth or rough surfaces. On such surfaces the solid puck will not travel far before it bounces, tumbles or starts rolling. They are easily upset by playing surface imperfections while being shot, passed or even just being pushed along with a hockey stick. Stick handling, moving the puck side to side with the stick, is impossible since the solid puck will not stay flat on the playing surface. A typical solid puck is disclosed in U.S. Pat. No. 5,275,410 Bellehumeur et al. (1994). Like most, it is the about the same size and shape as an ice hockey puck. The main body is made up of an elastic material and embedded in this material are runners. The runners project out of the body and are made from materials with low friction and good wear characteristics.
The intended function of the projecting runners is to reduce friction. Their unintended function is to get caught in the many imperfections found in the playing surfaces. In concrete they cause the puck to trip on cracks and expansion joints. In asphalt the imperfections are usually holes which the projecting runners can easily fall into and upset the puck. On a surface like a nicely finished tennis court these solid pucks perform fine. On the typical surface available to most kids, most solid pucks are nearly unusable.
A further example is a hockey puck as defined under U.S. Pat. No. 5,792,012 by Dudley which described a hockey similar to the improved hockey puck of the present invention however without a fortifying member within either disks of the hockey puck. The hockey puck under Dudley cannot withstand extreme pressure that might be encountered when a player deploys a slap shot. The presence of the fortifying member allows for the improved hockey puck to withstand such force encountered when a player hits a slap shot.